Well head equipment



March 13, 1962 Filed May 20, 1957 J. M. LEBEAUX 3,025,083

WELL HEAD EQUIPMENT 4 Sheets-Sheet 1 dacob Lebeaux {aim ATTOR/VEVJ March 13, 1962 J. M. LEBEAUX 3,025,083

WELL HEAD EQUIPMENT Filed May 20, 1957 4 Sheets-Sheet 2 INVENgE. WW

ATTORNEYS J. M. LEBEAUX WELL HEAD EQUIPMENT March 13, 1962 4 Sheets-Sheet 3 Filed May 20, 1957 Jacob M Lebecrux $72 2; Y %W?/% ATTOfiA/EKS March 13, 1962 J. M. LEBEAUX 3,025,083

WELL HEAD EQUIPMENT Filed May 20, 1957 4 Sheets-Sheet 4 Jacob M ZebecM/ mgggm I A TTOR/VE Y3 3,025,083 Patented Mar. 13, 1962 3,025,083 WELL HEAD EQUIPMENT Jacob M. Lebeaux, Houston, Tex., assignor to Oil Center Tool Company, Houston, Tex., a corporation of Texas Filed May 20, 1957, Ser. No. 660,409 11 Claims. (Cl. 285-48) This invention relates to well heads and more particularly to tubing head assemblies for suspending production tubing from the well head. In one important aspect, it relates to a well head assembly and to a tubing hanger for suspending plural tubing strings. In another important aspect, it relates to a tubing head which is especially adapted to suspend plural tubing strings and yet may be used to suspend a single tubing string.

In recent years many petroleum producing wells have been completed for production from more than one formation. Good production procedure as well as the regulations of State authorities require that production from each formation be separately handled. This necessitates plural production strings and gives rise to special problems in suspending the strings from the well head equipment at the surface.

In single or plural string completion, it is most desirable to be able to suspend the string by a hanger which both seals with and is suspended by a tubing head. With this preferred suspension, the drilling control equipment may be removed without danger upon landing and tiedown of the tubing and the Christmas tree flanged on the tubing head.

Plural strings must be run one at a time. After one string is run, it must be landed, but room must be left in the tubing head to run and land another string. Space to run a second string is particularly acute when it is desired to run gas lift valves etc. on the second string.

Preferably in running two strings, the hanger for the first string should occupy only one-half of the bore through the tubing head to leave ample room for running gas lift valves, etc. past the landed hanger section.

This invention provides well head equipment having both of the above discussed desirable features. The invention provides a tubing hanger assembly for plural completion in which each tubing string is supported by a separate segment of a tubing hanger. A seal, preferably self energizing, is provided bet-ween the hanger segments and between the hanger and tubing head.

As a hanger segment is run on a tubing string into the tubing head, it is supported above the tubing head bowl and positively held against the wall of the tubing head to assure a full open passageway through the remainder of the bowl for running another string through the tubing head. Two groups of cam members are provided for holding a hanger section against the sidewall of the bowl. One group of cams is arranged so that the cams will ordinarily perform the desired function, but if necessary the two groups of cams may be utilized and will positively drive the hanger section into full contact with the wall of the tubing head.

This invention also provides a well head assembly for plural string completion in which split hanger sections are held slightly above unlanded position until all of the strings have been run. Then the hanger sections are lowered, preferably simultaneously, into fully seated position in the tubing head. This is of particular advantage when the assembly employs a self energizing seal, but it will be appreciated that simultaneous landing of the hanger sections will be advantageous regardless of the type of seal means employed.

Plural completion requires orientation of the tubing hanger to interconnect the plural tubings with particular flow outlets of the Christmas tree. This orientation may be provided by lugs or the like projecting into the tubing head. Such lugs prevent the use of the tubing head for any other type of completion. The tubing head is made up as a part of well head equipment long before the well is drilled to the producing zones, and the operator is not sure how many zones he may wish to produce until he has tested the most promising formations. However, he has heretofore been committed by the type of tubing head made up in the well head equipment or has been faced with the necessity of either replacing the original tubing head, which is dangerous, or using a tubing head other than in its intended manner.

This invention provides a tubing head which may be used for either single or plural string completion. Where plural string completion is found to be desirable, a plural string hanger, as taught by this invention, may be used. When it is found that only one formation is to be produced, then the tubing head may be used to support a conventional single string tubing hanger. The tubing head works equally well with either type of completion.

It is an object of this invention to provide a well head assembly for suspending plural tubing strings individually from sections of a longitudinally split tubing hanger in which self-energizing seals are provided and seal between the sections of the tubing hanger and between the tubing hanger and well head.

Another object is to provide a tubing hanger made up in sections, each of which is adapted to suspend a tubing string and, when assembled to form a tubing hanger for landing in a tubing head in which self-energizing seals are carried by each section of the tubing hanger and seal between the sections of the hanger and between the tubing hanger and Well head.

Another object is to provide a well head assembly having a longitudinally segmented tubing hanger for suspending plural strings of tubing in which means are provided in the tubing head for individually suspending each section of the tubing hanger above landed position and after all strings are run to lower all of the hanger sections to fully landed position.

Another object is to provide a well head assembly for plural string completion in which the tubing strings are suspended from sections of a longitudinally split hanger, and the split hanger sections, after they are run, are held slightly above fully landed position and in firm engagement with the wall of the tubing head to provide maximum space for running subsequent strings of tubing.

Another object is to provide a tubing head assembly for plural string completion in which the tubing hanger is split longitudinally into sections, each of which supports a tubing string, and the sections are separately run and supported in the well head at a position slightly above fully-landed position and held against the side wall of the bowl to provide maximum passageway through the tubing head and in which the means for holding the hanger section slightly above landed position provide means for lowering them to landed position and additionally provide a part of the means for holding the hanger sections against the side wall of the tubing head.

Another object is to provide a well head assembly for plural completion employing a segmented tubing hanger in which means are provided in addition to the conventional bowl for supporting the tubing hanger, particularly during test of the seal to avoid the test pressure jamming the segmented hanger downwardly into the bowl.

Another object is to provide a well head assembly in which the tubing head may be used with a special split hanger to support plural strings of tubing or may be used with a conventional hanger to support a single string of tubing.

Other objects, features, and advantages of the invention will appear from the drawings, the specification, and the claims.

In the drawings wherein there is shown an illustrative embodiment of this invention, and wherein like reference numerals indicate like parts:

FIGURE 1 is a view in vertical cross-section through a well head assembly constructed in accordance with this invention;

FIGURE 2 is a view along the line 2-2 of FIGURE 1, showing the aligning screws which align, land and support the tubing hanger;

FIGURE 3 is an isometric view of the tubing hanger of FIGURE 1;

FIGURE 4 is a view along the line 4-4 of FIGURE 1, illustrating the hold-down cams;

FIGURE 5 is a view along the line 5-5 of FIGURE 4, illustrating the downward cam action of the hold-down cams;

FIGURE 6 is a sectional view through a fragment of a tubing head on a reduced scale, showing one tubing hanger segment to be supported in the tubing head slightly above landed position by means carried by the tubing head;

FIGURE 7 is a view similar to FIGURE 6 showing the supporting means out of engagement with the hanger section and the hanger section to be in fully landed position;

FIGURE 8 is a view similar to FIGURE 6 and taken 90 therefrom, illustrating the manner in which the aligning means, as well as the hold-down means, holds the first run hanger section firmly against the side wall of the tubing head to provide a full opening for running the second string of tubing;

FIGURE 9 shows both sections of the hanger employed in the illustrative embodiment of this invention in position after both strings of tubing have been run with both hanger sections supported on means carried by the tubing head preparatory to simultaneous lowering of the tubing hanger sections to fully landed position as shown in FIGURE 1;

FIGURE 10 illustrates the tubing head of this invention with a conventional single string tubing hanger landed therein to illustrate the manner in which the tubing head of this invention may be used to run a single string of tubing.

Referring now to the drawings, the tubing head, indicated generally at 19, has a longitudinal bore Ill therethrough to provide for the running of one or more strings of tubing into the well. A portion of the bore II is provided by a tapered bowl section I2 which is adapted to support the tubing hanger indicated generally at 13, as. well as the conventional single string hanger indicated generally at I4 in FIGURE It).

The tubing hanger of this invention is longitudinally split into sections, one for each string of tubing to be run. As best shown in FIGURE 1, each tubing hanger section and 16 supports a string of well tubing 17 and 18, respectively. The several hanger sections, when assembled together, form a tubular hanger adapted to seat in the tubing head in the usual manner.

In the form of hunger illustrated in this invention, two tubing strings are being run; therefore, there are two sections of the tubing hanger. Each of these sections is identical, and the tubing hanger might be described as a body having an external contour which mates with the section of bore 11 in the well head which contains bowl 1?. and with the tubing hanger split into two identical halves along a longitudinal diametrical plane of the bore through the tubing hanger. This provides coplanar abutent faces on the tubing hanger sections, one of which is shown at 19 on hanger section 16 (FIG. 3}.

Means are provided for sealing between the hanger sections and between the tubing hanger and tubing head. This means is preferably a self-energizing seal which is energized by landing of the tubing hanger in the bowl of the tubing head. In the preferred form shown, the selfenergizing seal is provided by a seal member 21 in a groove 22 extending about each hanger section. The seal member extends slightly beyond the peripheral face of the hanger section so that, upon seating of the hanger assembly, the seal member will be pressurized to form a seal between the sections of the hanger and between the hanger and tubing head.

It will be noted that the seal means is carried by each hanger section in the frusto-conical portion 23 of the tubing hanger; that is, the portion of the tubing hanger which mates with the bowl section 12 of the tubing head. Thus the weight of the strings upon the tubing hanger is partially transmitted through the seal means to the tubing head. In transmission of this weight, the seal means is compressed and forms a seal between the hanger sections and between the hanger and tubing head.

Production tubing are run One string at a time. In employing the dual hanger illustrated in the drawings, one of the hanger sections 15 or 16 will be made up on a string of tubing 17 or 18, respectively, as it is run in the hole and will be lowered into the well head. If tolerances are maintained very fine, it might be possible to land the hanger section without the wedge surfaces provided by the bowl 12 and the portion 23 of the hanger section, forcing the hanger section across the bore of the tubing head to obstruct running of the second hanger section. However, tolerances are not normally maintained this fine. The tubing heads and tubing hangers are mass produced and not matched to each other. Therefore, it is desirable to force the first tubing hanger section run in the well head to remain firmly against the side wall of the tubing head and leave ample room for the running of the second section of the tubing hanger.

It is also desirable to orient the tubing hanger sections in the well head for fluid communication with the outlets from the well head. For this purpose, an aligning means should be provided which engages the hanger sections and prevents their being landed in other than the proper orientation.

For the two purposes discussed above, there are provided aligning means carried by the tubing head which engage the hanger sections as they are run in the tubing head. The aligning means forces the hanger sections into proper oriented position, as well as holds them firmly against the side wall of the tubing head. This aligning means is preferably provided by cam means, indicated generally at 24 and 25. The aligning means are carried by the tubing head below the bowl section 12. The cam elements are provided by bolts 26 positioned on opposite sides of the tubing head. Each bolt has a cam surface 27 on its nose section which engages a complementary cam surface 25 on the tubing hanger sections whereby the hanger sections are firmly wedged against the side wall of the tubing head. The contour of the cam surface 27 carried by the bolt is conical in form, and the cam surfaces on each of the tubing hanger sections are rovided by beveling the lower corners of each hanger section at the juncture between the coplanar faces 19 and the semi-circular surface of the hanger section.

The cam means is carried in the tubing hanger by a conventional gland assembly indicated generally at 29.

Even with close tolerances, it would be difilcult to first fully land one hanger section so that it occupied a full onehalf of the space in the bore 11 and to then run and land a second half of the tubing hanger. This is particularly true where self-energizing seals are employed. The portion of the seal carried by the plane face 19 would tend to be shaved off by the incoming second half of the hanger-if the second half of the hanger could be forced past the first half.

To avoid any difficulty in landing the successive hanger sections, movable ledge means are provided for maintaining the previously run hanger section slightly above landed position so that the bowl does not tend to force the landed hanger section across the bore in the tubing head. Preferably, this means is provided by the aligning means 24 and 25. When the first hanger section is run, the aligning means is projected into the bore a sufficient distance to engage the cam surfaces 28 on the tubing hanger section being run and prevent its moving downward to fully seated position. Then, after all the hanger sections are run, the aligning means are backed 01? to simultaneously lower the hanger sections to fully seated position. Note from FIGURE 2 that each aligning means engages both the halves of the hanger sections and that both aligning means must be retracted before the tubing hanger can move downward to fully seated position. Therefore, the two halves will move simultaneously under the weight of the strings supported by the halves to fully seated position.

Hold-down means are provided for locking the hanger sections in fully seated position. Preferably these holddown means also function to hold each hanger section firmly against its adjacent side wall. It is further preferred that the hold-down means be capable of functioning with the hanger sections in their run, but unlanded, position; in other words, when supported upon the aligning bolts, so that if the first run hanger section tends to tilt outwardly into the bowl, the hold-down bolts may be utilized to firmly urge the hanger section against the side wall of the tubing head. Such hold-down bolts are provided in the tubing head and are arranged circumferentially about the head and above the bowl 12. These bolts are shown at 30, 31, 32, and 33. The hold-down bolt assemblies are identical, and each hold-down bolt is provided with a conical nose section 34 and an adjacent frusto-conical section 35. It will be noted that the holddown bolts are four in number and are positioned one on each side of each of the aligning bolts 24 and 25. Note FIGURE 4 in which aligning bolt 25 is shown in dashed lines. Each of the hanger sections is provided with holes which are arranged to receive the hold-down bolts and provide outwardly flaring cam surfaces for engagement by the cam noses of the hold-down bolts. Thus, hanger section 15 is provided with a hole 36 for receiving the cam nose of hold-down bolt 30 and with a second hole 37 for receiving the cam nose of opposed hold down bolt 31. Likewise, cam section 16 is provided with a hole 38 for receiving hold-down bolt 33 and a second hole 39 for receiving hold-down bolt 32.

Referring particularly to FIGURE 4, it will be noted that the arrangement of the hold-down bolts and the cam surfaces provided by the holes in the hanger sections is such that the adjacent side walls of the holes 36 and 37, in a circumferential sense, are engaged by the cam surfaces on the hold-down bolts 30 and 31. Thus, as the holddown bolts are run in, they urge the hanger section radially outward into engagement with the side wall of the tubing hanger. The same arrangement of bolts and holes is provided for hanger section 16, and the running in of bolts 32 and 33 will likewise force hanger section 16 against the side wall of the tubing head.

Preferably, the cam surfaces on the hold-down bolts are dimensioned to engage the hanger sections when they are supported in an unseated position by the aligning bolts 24 and 25. As the first hanger section is run into the well head, the hold-down bolts may be run in to hold the hanger section firmly on the aligning bolts and firmly against the side wall of the tubing head. Note FIGURE in which the hold-down bolts are also shown to be so arranged relative to the holes in the hanger sections that they also engage the sides of the holes in the hanger sections adjacent the seals 21, that is the downward side of the holes, and function to drive the hanger sections downwardly.

The operation of this invention is perhaps best illustrated by consideration of FIGURES 6, 7, 8, 9, and 1. Assuming the first string run to be tubing string 17, the tubing hanger section 15 is run into the tubing head until it rests upon the aligning bolts 24 and 25. The aligning bolts have previously been run into the tubing head a sufiicient distance to support the hanger section 15 slightly above landed position, as best illustrated in FIGURE 6. By feel, the operator will be able to determine that he cannot rotate the tubing hanger without raising it when it is properly oriented, that is, supported on the beveled cam surfaces by the aligning bolts. The tubing string is run through blowout preventers and the op erator is unable to see the position of the tubing hanger. Therefore, to insure that it is in an out of the way position and will not interfere with the running of subsequent tubing-hanger sections, the hold-down bolts 30 and 31 may be run in if desired until they force the tubing hanger against the side wall of the tubing head. These bolts will quickly be difiicult to turn and signal the operator that the hanger section is in proper position and is held firmly against the side wall of the tubing head.

After the first string is firmly supported in position, the second string may be run in the usual manner, as illustrated in FIGURE 8, until the second hanger section 16 rests upon the aligning bolts, as illustrated in FIGURE 9. As a full half of the tubing head bore is available exterior gas lift valves, oversize mandrels, etc. may be run on the second string.

With all of the hanger sections resting upon the aligning bolts, the hanger may be lowered into fully seated position by retracting the two aligning bolts until the hanger sections moving simultaneously downward in the tubing head, rest upon the bowl 12. At this time, the downward force exerted by the weight of the tubing strings will compress the self-energizing seal means to form a seal between the hanger section and between the tubing hanger and tubing head.

With the aligning bolts out of engagement with the tubing hanger, the four hold-down bolts may be run up tight to lock the tubing hanger in place.

With the tubing hanger landed and held in position by the tie-down bolts, and with conventional back pressure valves (not shown) in the tubing hanger sections, the blowout preventers (not shown) may be removed from the tubing head and the Christmas tree installed for flowing the well.

A portion of the tree is represented by the bonnet indicated generally at 41, which is flanged to the tubing head. Carriers 42 and 43 bridge the space between hanger sections 15 and 16, respectively, and bonnet 41. Laurent metal seal rings 44, on the top and bottom of the carriers 42 and 43, seal between the carriers and the bores through the hanger sections and between the carriers and the bores through the bonnet 41. Thus the flow is conducted separately from each fiow tubing through the bores in the hanger sections to separate outlets in the bonnet. A metal seal 45 is also provided between the flange sections of bonnet 41 and tubing head 10.

After the well head assembly has been completed, it is desirable to test the self-energizing seal carried by the tubing hanger, as well as the Laurent seals. For this purpose, a passageway 46 extends from the exterior of bonnet 41 to a point inwardly of the ring seal 45, where it communicates with the bore in the tubing head. A grease fitting 47 is provided in the passageway 46 for admission of testing pressure to the assembly.

It is preferred to test the seals under several thousand pounds of pressure, which would possibly drive the tubing hanger downwardly in the tubing head. This is undesirable. To avoid this possibility, the aligning screws are run in to firm engagement with the tubing hanger, where they provide additional support against downward movement of the tubing hanger. The seals may then be tested to insure that they are holding without driving the tubing hanger downward in the tubing head. If the seals are holding properly, the back pressure valves may be pulled from the tubing hanger and the well placed on production.

It will be appreciated that after both tubing strings have been run, either tubing may be manipulated or pulled. Thus, either string may be pulled first or packer may be set by manipulation of either string, etc.

During drilling of the well, the operator may have a good idea as to the number of formations to be produced, particularly if he is in a well-developed field. On the other hand, where detailed knowledge of the formations is not present, the operator will have no way of knowing whether he will wish to produce one or more formations. When elevated pressures are encountered in the well, it is dangerous to remove the blowout preventers which are above the tubing head topermit changing the tubing head made up in the well head. For this reason, it is desirable that the tubing head be one which functions equally well to support either one or more strings of tubing. The tubing head illustrated in this application is particularly well adapted to permit an operator to decide at the last moment whether he wishes to produce one or more formations without the necessity of changing the tubing head.

Reference is made to FIGURE in which the tubing head is shown supporting a conventional type of tubing hanger 14 for supporting a single string. In this case, the four hold-down bolts function in the usual manner to exert a downward component of force and lock the hanger in place. The tubing hanger has an outer periphery which generally conforms to the periphery of the split tubing hanger and seals with the bowl section 12 with self-energizing seals. The aligning bolts may be retracted to an out of the way position Where they do not interfere with free usage of the tubing head in landing a single. string of tubing.

It is believed apparent that other conventional types of single or dual string hangers may be used with equal facility with the tubing head, as the head is conventional in form with the exception of the aligning bolts and the hold-down bolts.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

l. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, movable ledge means carried by the tubing head for supporting each section of the tubing hanger above fully landed position and for lowering the hanger sections to fully landed position and seal means on one of the tapered bowl portions of the tubing head and the tapered section of the tubing hanger.

2. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, movable cam means carried by the tubing head engageable with each hanger section at circumferentially spaced points for supporting each section of the tubing hanger above fully landed position with the cam means in one position and for lowering the hanger sections simultaneously to fully landed position upon movement of the cam means to another position, and seal means on one of the tapered bowl portions of the tubing head and the tapered section of the tubing hanger.

3. A Well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, and movable cam means carried by the tubing head engageable with each hanger section at circumferentially spaced points for supporting each section of the tubing hanger above fully landed position with the cam means in one position and for lowering the hanger sections simultaneously to fully landed position upon movement of the cam means to another position, said cam means having a surface inclined relative to the central axis of the tubing head for engaging and urging each tubing hanger section into contact with the wall of the tubing head and seal means on one of the tapered bowl portions of the tubing head and the tapered section of the tubing hanger.

4. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split 1ongitudinally into sections, each section having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, movable ledge means carried by the tubing head for supporting each section of the tubing hanger above fully landed position and for lowering the hanger sections to fully landed position, and self-energizing seal means between the tapered bowl of the tubing head and the tapered sections of the tubing hanger sections and between the sections of the hanger forming a. continuous seal between the head and hanger and between the hanger sections, said self-energizing seal means carried by one of the tubing head bowl and the tubing hanger and extending outwardly beyond the adjacent surface thereof whereby the seal means is compressed upon landing of the tubing hanger.

5. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each section having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, movable ledge means carried by the tubing head for supporting each section of the tubing hanger above fully landed position and for lowering the hanger sections simultaneously to fully landed position, and self-energizing seal means carried by the tubing hanger sections extending in part along the tapered sections thereon and sealing between the tubing head and tubing hanger and between the sections of the hanger when the tubing hanger is fully landed in the tubing head, said self-energizing seal means carried by one of the tubing head bowl and the tubing hanger and extending outwardly beyond the adjacent surface thereof whereby the seal means is compressed upon landing of the tubing hanger.

6. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each section having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, movable cam means carried by the tubing head for individually supporting each section of the tubing hanger above fully landed position with the cam means in one position and for lowering the hanger sections simultaneously to fully landed position upon movement of the cam means to another position, selfenergizing seal means carried by the tubing hanger sections extending in part along the tapered sections thereon and sealing between the tapered bowl portion of the tubing head and the hanger and between the sections of the hanger when the tubing hanger is fully landed in the tubing head, said self-energizing seal means carried by one of the tubing head bowl and the tubing hanger and extending outwardly beyond the adjacent surface thereof whereby the seal means is compressed upon landing of the tubing hanger, and hold-down means provided by pairs of opposed spaced bolts supported in the tubing head and having frusto-conical cam surfaces for engaging cam surfaces on each hanger section and exerting a downwardly and radially outward force on each hanger section, both when the sections are suspended above fully landed position, if desired, and when the sections are in fully landed positions.

7. A tubing head comprising, a body, a bore through the body, a tapered bowl section providing a portion of the bore adapted to support a tubing hanger, a plurality of hold-down bolts in the body and projecting into the bore above the bowl, said bolts having cam portions for locking a tubing hanger in the bowl, and a plurality of aligning bolts in the body and projecting into the bore below the bowl, said aligning bolts having cam portions for aligning and supporting against downward movement longitudinally split hanger sections for dual string completion, said aligning bolts retractable from the bore into an out of the way position when landing a tubing hanger in the head which does not require the utilization of aligning bolts.

8. A well head assembly for plural string completion comprising, a tubing head having a bore therethrough including a tapered bowl portion for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered portion for landing in said tapered bowl and adapted to suspend a tubing string, seal means on one of said tapered bowl and the tapered portion of the tubing hanger and between the hanger sections, circumferentially spaced movable ledge means mounted in the tubing head and having portions in said bore engaging and supporting the tubing hanger above fully landed position in one position of the ledge means and for lowering the tubing hanger to fully landed position in the tubing head with movement of the ledge means to a second position, each of said hanger sections supported by two of said movable ledge means, one of said hanger sections and movable ledge means at points of engagement therebetween providing surfaces inclined relative to the axis of the bore for wedging the hanger sections radially outward into engagement with the tubing head when the ledge means are in the first position.

9. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, and movable ledge means carried by the tubing head for supporting each section of the tubing hanger above fully landed position and for lowering the hanger sections to fully landed position.

10. A well head assembly for plural string completion comprising, a tubing head having a tapered bowl therein for supporting a tubing hanger, a tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each of said sections having a tapered section for landing in said tapered bowl and adapted to suspend a tubing string, and movable cam means carried by the tubing head engageable with each hanger section at circumferentially spaced points for supporting each section of the tubing hanger above fully landed position with the cam means in one position and for lowering the hanger sections simultaneously to fully landed position upon movement of the cam means to another position.

11. A well head assembly for plural string completion comprising, a tubing head having a bore therein, a tapered bowl in the bore from which tubing may be suspended, at tubing hanger dimensioned to be supported in the tubing head and split longitudinally into sections, each section having a bore therethrough and adapted to suspend a tubing string in fluid communication with the bore, opposed wedge elements in the bore of the tubing head, said wedge elements provided by a plurality of bolts mounted in the tubing head and having cam portions projecting into the bore of the head, said bolts retractable into an out-of-the-way position when landing a tubing hanger in the tubing head which does not require the utilization of said bolts, wedge surfaces on each tubing hanger and inclined relative to the bore therethrough for engaging said wedge elements, said wedge elements engaging the wedge surfaces on the first-run hanger section as it is lowered into the head, said wedge elements and surfaces cooperating to support and wedge the first-run segment into firm contact with the wall of the tubing head, each of said wedge elements engaging two of said hanger sections.

References Cited in the file of this patent UNITED STATES PATENTS 

